Yes, a full time student is defined by the IRS.
Full-time student. A full-time student is a student who is enrolled for the number of hours or courses the school considers to be full-time attendance. The 5 calendar months don't have to be consecutive or full months. Some part of 5 different months.
School defined. A school can be an elementary school, junior or senior high school, college, university, or technical, trade, or mechanical school. However, an on-the-job training course, correspondence school, or school offering courses only through the Internet doesn’t count as a school.
